Computing devices, such as notebook computers, personal data assistants (PDAs), kiosks, and mobile handsets, have user interface devices, which are also known as human interface devices (HID). One user interface device that has become more common is a touch-sensor pad (also commonly referred to as a touchpad). A basic notebook computer touch-sensor pad emulates the function of a personal computer (PC) mouse. A touch-sensor pad is typically embedded into a PC notebook for built-in portability. A touch-sensor pad replicates mouse x/y movement by using two defined axes which contain a collection of sensor elements that detect the position of a conductive object, such as a finger. Mouse right/left button clicks can be replicated by two mechanical buttons, located in the vicinity of the touchpad, or by tapping commands on the touch-sensor pad itself. The touch-sensor pad provides a user interface device for performing such functions as positioning a pointer, or selecting an item on a display. These touch-sensor pads may include multi-dimensional sensor arrays for detecting movement in multiple axes. The sensor array may include a one-dimensional sensor array, detecting movement in one axis. The sensor array may also be two dimensional, detecting movements in two axes.
One type of touch pad operates by way of capacitance sensing utilizing capacitive sensors. The capacitance detected by a capacitive sensor changes as a function of the proximity of a conductive object to the sensor. The conductive object can be, for example, a conductive stylus or a user's finger. In a touch-sensor device, a change in capacitance detected by each sensor in the X and Y dimensions of the sensor array due to the proximity or movement of a conductive object can be measured by a variety of methods. Regardless of the method, usually an electrical signal representative of the capacitance detected by each capacitive sensor is processed by a processing device, which in turn produces electrical or optical signals representative of the position of the conductive object in relation to the touch-sensor pad in the X and Y dimensions. A touch-sensor strip, slider, or button operates on the same capacitance-sensing principle.
Another user interface device that has become more common is a touch screen. Touch screens, also known as touch screens, touch panels, or touch screen panels are display overlays which are typically either pressure-sensitive (resistive), electrically sensitive (capacitive), acoustically-sensitive (SAW—surface acoustic wave) or photosensitive (infra-red). The effect of such overlays allows a display to be used as an input device, removing the keyboard and/or the mouse as the primary input device for interacting with the display's content. Such displays can be attached to computers or, as terminals, to networks. There are a number of types of touch screen technologies, such as optical imaging, resistive, surface acoustical wave, capacitive, infrared, dispersive signal, piezoelectric, and strain gauge technologies. Touch screens have become familiar in retail settings, on point of sale systems, on automated teller machines (ATMs), on mobile handsets, on kiosks, on game consoles, on PDAs where a stylus is sometimes used to manipulate the graphical user interface (GUI) and to enter data, and in automobile liquid crystal displays (LCDs).
Conventional user interface devices, however, do not have the ability to limit an operator at a certain location from interacting with a user interface of the device. Also, conventional user interface devices do not have the ability to provide one type of interaction with a user in one location, and a different interaction for another user in a different location, for example, a user in a driver seat and a passenger in a passenger seat in a car. These conventional devices are not configured to determine who has pressed a button (e.g., on a capacitive sensor or touch screen) in order to, for example, prevent the driver from accessing navigation functions while the car is in motion, but allow the passenger to operate those same controls.